Note 16 - New Authoritative Accounting Pronouncements (Details Textual) - USD ($)		3 Months Ended
	Jan. 01, 2019	Mar. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset			$ 42,557,000	$ 0
Operating Lease, Liability, Total			$ 50,898,000	$ 0
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset	$ 45,400,000
Operating Lease, Liability, Total	54,000,000.0
Impact of Adoption of Accounting Standards Update		$ 2,716,000
Accounting Standards Update 2016-02 [Member] | Deferred Gain on Sale of Buildings Reclassified to Retained Earnings [Member]
Impact of Adoption of Accounting Standards Update	$ 2,700,000